title: Normalized T1 magnetic resonance imaging for assessment of regional lung function in adult cystic fibrosis patients--a cross-sectional study.
abstract: BACKGROUND
  Cystic fibrosis (CF) patients would benefit from a safe and effective tool to detect early-stage, regional lung disease to allow for early intervention. Magnetic Resonance Imaging (MRI) is a safe, non-invasive procedure capable of providing quantitative assessments of disease without ionizing radiation. We developed a rapid normalized T1 MRI technique to detect regional lung disease in early-stage CF patients.
  
  
  METHODS
  Conventional multislice, pulmonary T1 relaxation time maps were obtained for 10 adult CF patients with normal spirometry and 5 healthy non-CF control subjects using a rapid Look-Locker MRI acquisition (5 seconds/imaging slice). Each lung absolute T1 map was separated into six regions of interest (ROI) by manually selecting upper, central, and lower lung regions in the left and right lungs. In order to reduce the effects of subject-to-subject variation, normalized T1 maps were calculated by dividing each pixel in the absolute T1 maps by the mean T1 time in the central lung region. The primary outcome was the differences in mean normalized T1 values in the upper lung regions between CF patients with normal spirometry and healthy volunteers.
  
  
  RESULTS
  Normalized T1 (nT1) maps showed visibly reduced subject-to-subject variation in comparison to conventional absolute T1 maps for healthy volunteers. An ROI analysis showed that the variation in the nT1 values in all regions was ≤2% of the mean. The primary outcome, the mean (SD) of the normalized T1 values in the upper right lung regions, was significantly lower in the CF subjects [.914 (.037)] compared to the upper right lung regions of the healthy subjects [.983 (.003)] [difference of .069 (95% confidence interval .032-.105); p = .001). Similar results were seen in the upper left lung region.
  
  
  CONCLUSIONS
  Rapid normalized T1 MRI relaxometry obtained in 5 seconds/imaging slice may be used to detect regional early-stage lung disease in CF patients.
authors.affiliation: Department of Pediatrics, Case Western Reserve University School of Medicine, University Hospitals Case Medical Center and Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America ; Department of Medicine, Case Western Reserve University School of Medicine, University Hospitals Case Medical Center and Rainbow Babies and Children's Hospital, Cleveland, Ohio, United States of America.
authors.forename: Elliott C
authors.initials: EC
authors.lastname: Dasenbrook
authors.forename: Lan
authors.initials: L
authors.lastname: Lu
authors.forename: Shannon
authors.initials: S
authors.lastname: Donnola
authors.forename: David E
authors.initials: DE
authors.lastname: Weaver
authors.forename: Vikas
authors.initials: V
authors.lastname: Gulani
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Michael W
authors.initials: MW
authors.lastname: Konstan
authors.forename: Chris A
authors.initials: CA
authors.lastname: Flask
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012129:Respiratory Function Tests; D055815:Young Adult